Mobile X-Ray Imaging System

ABSTRACT

A mobile diagnostic imaging system includes a battery system and charging system. The battery system is located in the rotating portion of the imaging system, and includes one or more battery packs comprising electrochemical cells. Each battery pack includes a control circuit that controls the state of charge of each electrochemical cell, and implements a control scheme that causes the electrochemical cells to have a similar charge state. The battery system communicates with a charging system on the non-rotating portion to terminate charge when one or more of the electrochemical cells reach a full state of charge. The imaging system also includes a docking system that electrically connects the charging system to the battery system during charging and temporarily electrically disconnects the rotating and non-rotating portions during imaging, and a drive mechanism for rotating the rotating portion relative to the non-rotating portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application is a Continuation of U.S. patent application Ser. No.17/147,130 filed on Jan. 12, 2021, which is a Continuation of U.S.patent application Ser. No. 15/674,842 filed on Aug. 11, 2017 and issuedas U.S. Pat. No. 10,925,559 on Feb. 23, 2021, which is a Continuation ofU.S. patent application Ser. No. 13/441,555 filed on Apr. 6, 2012 andissued as U.S. Pat. No. 9,737,273 on Aug. 22, 2017, which claims benefitof U.S. Provisional Application 61/473,102 filed on Apr. 7, 2011, thedisclosures of each of which are hereby incorporated by reference intheir entirety.

BACKGROUND

Conventional medical imaging devices, such as computed tomography (CT)and magnetic resonance (MR) imaging devices, are typically fixed,immobile devices located in a discrete area reserved for imaging that isoften far removed from the point-of-care where the devices could be mostuseful.

It would be desirable to make these imaging devices mobile, so that theycan move to various locations within a hospital or other health servicesenvironment. This is difficult due to the size, weight and overallnumber of components required for making an operable imaging system.Furthermore, these systems typically require a power system that canprovide high-voltages (e.g., 120 kV) to components that rotate withinthe system around an imaging bore. Conventional imaging systemsgenerally utilize a dedicated high-voltage power source and a complexpower delivery mechanism, such as a slip-ring or a high-voltage cablesystem, to deliver the required power to the rotating imagingcomponents. While these power systems may work fine for conventionalfixed imaging systems, they are not ideal for mobile systems, which areideally much more compact and lightweight than conventional systems.Furthermore, when transporting a mobile system outside of thetraditional radiology environments, it is typically not possible toobtain the power required to perform imaging procedures from standardpower outlets.

SUMMARY

Various embodiments include an imaging system that comprises a rotatingportion comprising a rotor and at least one imaging component mounted tothe rotor, and a gantry comprising an outer shell that substantiallyfully encloses the rotating portion over one or more sides of therotating portion, the outer shell further comprising a mounting surfacefor a bearing that enables the rotating portion to rotate 360° withinthe outer shell.

In further embodiments, a mobile diagnostic imaging system may include abattery system and charging system. The imaging system may include afirst portion and a second portion, wherein the first portion rotateswith respect to the second portion. In one embodiment, the rotatingportion rotates within an enclosed housing of a gantry.

In embodiments, the battery system may be located in the rotatingportion of the system. The battery system may include one or morebattery packs, each comprising one or more electrochemical cells. Eachbattery pack may further include a control circuit that monitors and/oralters the state of charge of each of the electrochemical cells. Thecontrol circuit may implement a control scheme that causes theelectrochemical cells to have a similar charge state. The battery systemmay include a communication network that allows the packs to communicatewith each other in order to implement the control scheme for causing theelectrochemical cells to be of similar charge state. In someembodiments, the battery packs are able to communicate with a mainbattery control circuit to implement the control scheme for causing theelectrochemical cells to be of similar charge state.

In embodiments, the charging system may be located on the non-rotatingportion of the system. The battery system may communicate with thecharging system to terminate charge when one or more of theelectrochemical cells reach a full state of charge. In some embodiments,the battery system communicates with a main battery control circuit toterminate charge when one or more of the electrochemical cells reach afull state of charge.

In further embodiments, the imaging system may also include a dockingsystem that selectively couples and decouples the rotating andnon-rotating portions of the system. The charging system charges thebattery system when the docking system engages to couple the rotatingand non-rotating portions of the system. During an imaging scan, thedocking system may temporarily electrically disconnect the rotating andnon-rotating portions of the system. The battery system may providepower to the rotating portion of the system while the docking system isdisengaged. In one embodiment, the charging system provides power to thenon-rotating portion of the imaging system while the docking system isdisengaged. Further embodiments relate to methods of docking andundocking the rotating and non-rotating components of an imaging system.

In further embodiments, the imaging system may also include anon-contact signaling system, such as an optical or magnetic system,that is provided at one or more discrete locations on both the rotatingand non-rotating portions of the system. The signaling system isprovided to coordinate the onset or termination of various functionswithin the system, such as motion or irradiation.

In further embodiments, the imaging system may include a drive mechanismfor rotating the rotating portion relative to the non-rotating portion.The drive mechanism may include a belt that is provided on thenon-rotating portion and a motorized system having a gear that isprovided on the rotating portion. The gear meshes with the belt, so thatwhen the gear is driven by a motor, the motorized system travels alongthe length of the belt, causing the rotating portion to which it isattached to rotate with respect to the non-rotating portion. The drivemechanism may be powered by the battery system.

In other embodiments, the present invention relates to methods ofdiagnostic imaging using an imaging system having rotating andnon-rotating portions.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will be apparentfrom the following detailed description of the invention, taken inconjunction with the accompanying drawings of which:

FIG. 1 is a perspective view of an X-ray CT imaging system in accordancewith one embodiment of the invention.

FIG. 2A is a perspective view of a gantry and gimbal.

FIG. 2B schematically illustrates the assembly of the gimbal and gantry.

FIG. 2C shows the gimbal and gantry of FIG. 2B fully assembled.

FIG. 3A is a cross-sectional schematic illustration of an imaging systemthat illustrates the rotating and non-rotating portions of the system.

FIG. 3B is an exploded view of the imaging system of FIG. 3A.

FIG. 4A is an exploded view of a gantry illustrating an outer shell, arotor and a bearing system according to one embodiment.

FIG. 4B is a perspective view of the assembled gantry.

FIG. 4C is a front elevation view of the gantry.

FIG. 4D is a side cross section view of the gantry.

FIG. 4E is a cross-section view of a portion of the gantry illustratinga bearing system in one embodiment.

FIG. 4F illustrates an arrangement of components on a rotor according toone embodiment.

FIG. 5 illustrates a battery pack control circuit according to oneembodiment of the invention.

FIG. 6A is a schematic illustration of the imaging system showing thebattery, charging and docking systems.

FIG. 6B schematically illustrates the power circuitry during a dockingprocedure of the system according to one embodiment.

FIG. 7 is a close-up view of FIG. 3A illustrating the charging systemmounted on the gimbal.

FIG. 8 is a perspective view of the gimbal with charging system.

FIG. 9A is a perspective view of an embodiment of the docking systemshown in a disengaged state.

FIG. 9B is a side elevation view of the docking system in a disengagedstate.

FIG. 10A is a perspective view of the docking system shown in an engagedstate.

FIG. 10B is a side elevation view of the docking system in an engagedstate.

FIG. 11A is a perspective view of the portion of the docking system thatis mounted to the rotor.

FIG. 11B is a front view of the portion of the docking system shown inFIG. 11A.

FIG. 12A is a perspective view of the portion of the docking system thatis mounted to the non-rotating portion of the imaging system.

FIG. 12B is a front view of the portion of the docking system shown inFIG. 12A.

FIG. 13A is a cross-section view of an imaging system showing thelocation of the docking system.

FIG. 13B is a close-up view of the docking system of FIG. 13A.

FIG. 14A is a perspective view of an imaging system showing the locationof the docking system.

FIG. 14B is a close-up view of the docking system of FIG. 14A.

FIG. 15 illustrates a non-contact signaling apparatus according to oneembodiment.

FIG. 16 is a cross-section view of an imaging system with a drivemechanism for driving the rotation of the rotor.

FIG. 17 is a perspective view of the imaging system illustrating therotor drive mechanism.

FIG. 18 is a magnified view of the rotor drive mechanism of FIG. 17 .

FIG. 19 is a perspective view of the drive mechanism showing a belt andmotorized gear system.

DETAILED DESCRIPTION

The various embodiments will be described in detail with reference tothe accompanying drawings. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.References made to particular examples and implementations are forillustrative purposes, and are not intended to limit the scope of theinvention or the claims.

This application claims the benefit of priority to U.S. ProvisionalApplication No. 61/473,102 entitled “Mobile X-Ray Imaging System” filedon Apr. 7, 2011. This application is also related to U.S. applicationSer. No. 12/576,681, filed Oct. 9, 2009, now U.S. Pat. No. 8,118,488,U.S. application Ser. No. 13/025,566, filed Feb. 11, 2011, and U.S.application Ser. No. 13/025,573, filed Feb. 11, 2011. The entirecontents of all of these applications are hereby incorporated byreference for all purposes.

Referring to FIG. 1 , a mobile imaging system 100 according to oneembodiment of the invention includes a mobile base 20, a gimbal 30, agantry 40, and a pedestal 50. The system 100 includes image collectioncomponents, such as a rotatable x-ray source and detector array orstationary magnetic resonance imaging components, that are housed withinthe gantry 40. The system 100 is configured to collect imaging data,such as, for example x-ray computed tomography (CT) or magneticresonance imaging (MRI) data, from an object located within the bore ofthe gantry 40, in any manner known in the medical imaging field. Thepedestal 50 is adapted to support a tabletop support 60 that can beattached to the pedestal 50 in a cantilevered manner and extend out intothe bore of the gantry 40 to support a patient or other object beingimaged.

The gantry 40 and gimbal 30 are illustrated in FIG. 2A. The gimbal 30 isa generally C-shaped support that is mounted to the top surface of base20 and includes a pair of arms 31, 33 extending up from the base. Thearms 31, 33 are connected to opposite sides of gantry 40 so that thegantry is suspended above base 20 and gimbal 30. In one embodiment, thegimbal 30 and gantry 40 can rotate together about a first axis (a)relative to the base 20, and the gantry 40 can tilt about a second axis(a′) relative to the gimbal 30 and base 20.

In certain embodiments, the gimbal 30 and gantry 40 can translate withrespect to the base 20 to provide an imaging scan. The gimbal 30 caninclude bearing surfaces that travel on rails 23, as shown in FIG. 1 ,to provide the translation motion of the gimbal 30 and gantry 20. A scandrive mechanism can drive the translation of the gantry and gimbalrelative to the base, and a main drive mechanism can drive the entiresystem in a transport mode. In the embodiment of FIG. 1 , both of thesefunctions are combined in a drive system 70 that is located beneath thegimbal 30.

In certain embodiments, the base 20 of the system can be omitted, andthe gimbal 30 can sit directly on the ground to support the gantry 40.In other embodiments, the gimbal can be omitted, and the gantry 40 is astand-alone gantry that sits on the ground.

FIG. 2B is an exploded view of the gimbal 30, illustrating how thegimbal 30 may be connected to the gantry 40 in various embodiments. Asshown in FIG. 2B, the gimbal 30 may be assembled from multiple pieces.Upper portions 201,203 of the gimbal 30 may be securely fastened toopposing sides of the gantry 40. The upper portions 201, 203, which mayhave a shape similar to “earmuffs,” may include a bearing apparatus thatenables the “tilt” motion of the gantry 40 relative to the gimbal 30.The upper portions 201,203 may also be fastened to the respective arms31, 33 of the gimbal 30. For ease of assembly, it may be preferable tofasten the upper portions 201, 203 to the gantry 40 before connectingthe entire gantry/upper portion assembly to the respective arms 31,33 ofthe gimbal 30. Also shown in FIG. 2B is a cover 205 that may be placedover an access opening in one or both arms 31, 33 of the gimbal 30. Anadditional cover 207 may be provided over the base of the gimbal 30, andmay be removed to access a bearing and/or drive system positioned withinor beneath the base of the gimbal 30.

FIG. 3A is a cross-sectional view of the gantry 40 and gimbal 30 thatillustrates a number of components of the imaging system 100, which inthis embodiment comprises an X-ray CT imaging system, including an x-raysource 43, high-voltage generator 44, x-ray detector 45, battery system63, computer 46, rotor drive mechanism 47, docking system 35 andcharging system 34. A number of these components, including the x-raysource 43, high-voltage generator 44, x-ray detector 45, battery system63, computer 46 and rotor drive mechanism 47, are mounted on a rotor 41,as is illustrated in the exploded view of FIG. 3B. The rotor 41 and thecomponents mounted thereto, rotate within a housing defined by an outershell 42 of the gantry 40.

The system 100 thus has a rotating portion 101, which includes the rotor41 and the various components mounted to the rotor that rotate withinthe gantry 40 during an imaging scan, and a non-rotating portion 103,that generally includes the other components of the system, includingthe base 20, gimbal 30, and the outer shell 42 of the gantry 40. Thecharging system 34 is located on the non-rotating portion 103 of thesystem. The docking system 35 provides intermittent connection betweenthe rotating and non-rotating portions 101, 103 for transfer of powerand/or data between the two portions.

During an imaging scan, the rotor 41 rotates within the interior of thegantry, while the imaging components such as the x-ray source 43 andx-ray detector 45 obtain imaging data for an object positioned withinthe bore of the gantry, as is known, for example, in conventional X-rayCT scanners. The rotor drive mechanism 47 drives the rotation of therotor 41 around the interior of the gantry 40. The rotor drive mechanism47 may be controlled by a system controller that controls the rotationand precise angular position of the rotor 41 with respect to the gantry40, preferably using position feedback data, such as from a positionencoder device.

Various embodiments of the imaging system 100 may be relatively compact,which may be desirable, for example, in a mobile imaging system. One wayin which the system 100 may be made compact is in the design of thegantry 40 and its interface with the rotating portion 101 (e.g., therotor 41 and the various components mounted to the . rotor 41). Inembodiments, the outer shell 42 of the gantry 40 may comprise both aprotective outer covering for the rotating portion 101 and a mountingsurface for a bearing that enables the rotating portion 101 to rotate360° within the outer shell 42 of the gantry 40.

FIG. 4A is an exploded view of a gantry 40 according to one embodimentthat illustrates the outer shell 42, the rotor 41 and a bearing assembly400. FIG. 4B illustrates the assembled gantry 40. As is shown in FIGS.4A-B, the outer shell 42 of the gantry 40 may be a generally O-shapedcovering of a structural material that may at least substantially fullyenclose the rotating portion 101, including the rotor 41 and anycomponents mounted to the rotor, over one or more sides of the rotatingportion 101. The outer shell 42 of the gantry 40 may be conceptuallyconsidered an “exoskeleton,” that both supports the rotating portion 101of the system 100, preferably in three dimensions, and also provides aprotective barrier between the rotating portion 101 and the externalenvironment. In embodiments, the outer shell 42 of the gantry 40 maysupport at least about 75%, such as more than 80%, and preferably morethan about 90%, such as more than 99%, and even more preferably 100% ofthe weight of the rotating portion 101 of the imaging system 100. Inembodiments, the outer shell 42 itself may be supported by one or moreother components, such as a gimbal 30, base 20 and/or drive mechanism70, as shown in FIG. 1 , for example. In other embodiments, the outershell 42 may be supported directly on the ground, for example, or viaother means, such as raised on a pedestal, table, cart or other support,or suspended or cantilevered from a wall, ceiling or other supportstructure. In certain embodiments, an outer shell 42 of the gantry 40that comprises both a protective outer covering for the rotating portion101 and a mounting surface for a bearing for rotation of the rotatingportion 101 may provide the gantry 40 with various degrees-of-freedom,such as the “tilt” motion about axis (a′) and/or rotation about axis (a)as shown in FIG. 2A, as well as translation motion for imagingapplications and/or transport of the gantry 40.

The outer shell 42 may be fabricated from a sufficiently rigid andstrong structural material, which may include, for example, metal,composite material, high-strength plastic, carbon fiber and combinationsof such materials. In preferred embodiments, the outer shell 42 may becomprised of a metal, such as aluminum. The outer shell 42 may bemachined or otherwise fabricated to relatively tight tolerances. Theouter shell 42 may be formed as a one piece, unitary component. In otherembodiments, the outer shell 42 may be comprised of multiple componentsand/or materials that may be joined using any suitable technique toprovide the shell 42.

The outer shell 42 may have an outer circumferential surface 406 thatmay extend around the periphery of the rotating portion 101 of thesystem 100 to substantially fully enclose the rotating portion 101around its outer circumference. As used herein, “substantially fullyenclose” means that the circumferential surface 406 encloses at leastabout 60%, such as at least about 70% (e.g., 75% or more), andpreferably at least about 80%, such as at least about 90% (e.g., between95% and 100%) of the rotating portion 101 around its outercircumference. As shown in FIG. 4B, for example, the outer shell 42 maysubstantially fully enclose the rotating portion while also includingone or more openings, such as opening 408 (where the gantry 40 issecured to the gimbal 30) and access opening 410.

The outer shell 42 may also include at least one side wall 412 that mayextend from the outer circumferential surface 406 to a bore 416 of thegantry 40 and may substantially fully enclose the rotating portion 101around one side of the rotating portion. In embodiments, the outer shell42 may include two side walls, one on each side (e.g., front and rear)of the gantry 40, and the two side walls may substantially fully enclosethe rotating portion 101 around two sides of the rotating portion. Inthe embodiment shown in FIGS. 4A-F the outer shell 42 includes a sidewall 412 on a first side (e.g., the front side) of the gantry 40. Asshown in FIGS. 4C-E, an opposite (e.g., rear) side wall 414 of thegantry 40 may be formed by the combination of the outer shell 42,bearing assembly 400, and/or the rear surface of the rotor 41. The sidewall 414 may substantially fully enclose the various components mountedto the rotor 41 around a side of these components. The outercircumferential wall 406 and the side walls 412 and 414 may define acavity 418, as shown in FIG. 4E, and the various components mounted tothe rotor 41 may rotate within the cavity 418. A protective outercovering may be provided over the rear side wall 414 and/or over theinterior circumference of the gantry 40 (e.g., around the outercircumference of the bore 416) to provide an additional barrier betweenthe rotating portion 101 and the external environment. The protectivecovering may be comprised of a thin, lightweight material, such asplastic.

As will be discussed in further detail below, the drive mechanism forthe rotating portion 101 of the imaging system may utilize a belt driveon the rotor 41, where the belt for the drive is mounted to a fixedrailing 81, as is shown in FIG. 4F. In various embodiments, a railing 81or similar fixed structure for the rotor drive 41 may be located on theinternal surface of side wall 412.

The bearing assembly 400 according to one embodiment is shown in FIGS.4A and 4E. In this embodiment, the bearing assembly 400 includes a firstrace 402 that may be securely fastened to the outer shell 42 of thegantry 40, and a second race 404 that may be securely fastened to therotor 41. A bearing element 420 (FIG. 4E) is provided between the firstrace 402 and the second race 404, and is configured to allow the secondrace 404 (along with the rotor 41 to which it is attached) to rotateconcentrically within the first race 402, preferably with minimalfriction, thereby enabling the rotor 41 to rotate with respect to theouter shell 42 of the gantry 40. In the exemplary embodiment of FIG. 4E,the bearing assembly 400 may abut against a lip 424 in the rotor, and aplurality of fastening members 426 (such as bolts) may be providedthrough the lip 424 and into the second race 404 around the periphery ofthe rotor 41 to securely fasten the rotor 41 to the bearing assembly400. The bearing assembly 400 may also be provided at least partiallywithin the outer circumferential wall 406 of the outer shell 42 andagainst a lip 422 in the outer shell 42 of the gantry 40. A plurality offastening members (similar to fastening members 426) may be providedthrough the lip 422 and into the first race 402 around the periphery ofthe outer shell 42 to securely fasten the outer shell 42 to the bearingassembly 400. A small gap 428 may be provided between lip 422 and lip424. In some embodiments, all or a portion of the bearing assembly 400may be integrally formed as a part of the outer shell 42 or of the rotor41, or of both. For example, the first race 402 may be formed as anintegral surface of the outer shell 42 and/or the second race 404 may beformed as an integral surface of the rotor 41. In various embodiments,the entire bearing assembly for enabling the rotation of the rotatingportion 101 with respect to the non-rotating portion 103 of the imagingsystem 100 may be located within the generally O-shaped gantry 40.

The outer diameter of the gantry 40 can be relatively small, which mayfacilitate the portability of the system 100. In a preferred embodiment,the outer diameter (OD in FIG. 4C) of the gantry 40 is less than about70 inches, such as between about 60 and 68 inches, and in one embodimentis about 66 inches. The outer circumferential wall 406 of the outershell 42 may be relatively thin to minimize the OD dimension of thegantry 40. In addition, the interior diameter of the gantry 40, orequivalently the bore 416 diameter (ID in FIG. 4C), can be sufficientlylarge to allow for the widest variety of imaging applications, includingenabling different patient support tables to fit inside the bore, and tomaximize access to a subject located inside the bore. In one embodiment,the bore diameter of the gantry 40 is greater than about 38 inches, suchas between about 38 and 44 inches, and in some embodiments can bebetween about 40 and 50 inches. In one exemplary embodiment, the borehas a diameter of about 42 inches. As shown in FIG. 4D, the gantry 40generally has a narrow profile, which may facilitate portability of thesystem 100. In one embodiment, the width of the gantry 40 (W) is lessthan about 17 inches, and can be about 15 inches or less.

A number of features of the various embodiments may facilitate thecompact size of the imaging gantry 40. For example, as previouslydiscussed the outer shell 42 of the gantry 40 may be a relatively thinyet rigid exoskeleton structure that provides a protective outercovering for the rotating components while simultaneously supporting therotating components in multiple dimensions as they rotate relative tothe outer shell 42. Various additional features are illustrated in FIG.4F, which illustrates the rotating portion 101 of the imaging system 100according to one embodiment. The various components, such as x-raysource 43, detector 45, high-voltage generator 44, heat exchanger 430,computer 46, battery system 63, docking system 35 and rotor driver 47,may be mounted to rotor 41 and configured to fit and rotate within theinternal cavity 418 of the gantry 40 shown in FIG. 4E. As shown in FIGS.3A and 4F, for example, this may include providing the drive mechanism47 within the interior cavity 418 of the gantry 40, which may aid inminimizing the outer diameter and width dimensions of the gantry 40while also enabling a relatively large bore diameter. Various othercomponents may be configured to facilitate a compact gantry design. Forexample, as shown in FIG. 4F, the high-voltage generator 44, which maybe one of the larger components of the rotating portion 101, may have atleast one surface 432,434 that is angled or curved to substantiallycorrespond with the curvature of the gantry 40 and/or bore 416. Anotherexample of a high-voltage generator 44 with an angled or curved outersurface is shown in FIGS. 3A-B. Similarly, the battery system 63 may behoused in a chassis having at least one surface 436,438 that is angledor curved to substantially correspond with the curvature of the gantry40 and/or bore 416. In this way, the outer diameter of the gantry may beminimized while also maintaining a relatively large bore diameter.

The imaging system 100 generally operates in a conventional manner toobtain images of an object located in the bore of the gantry. Forexample, in the case of an x-ray CT scan, the rotor 41 rotates withinthe housing of the gantry 40 while the imaging components, including thex-ray source and x-ray detector, obtain image data at a variety of scanangles. Generally, the system obtains image data over relatively shortintervals, with a typical scan lasting less than a minute, or sometimesjust a few seconds. During these short intervals, however, a number ofcomponents, such as the x-ray source tube and the high-voltagegenerator, require a large amount of power, including, in someembodiments, up to 32 kW of power.

In one embodiment, the power for the rotating portion 101 of the system100 is provided by a battery system 63 that is located on the rotatingportion 101 of the system 100. An advantage of the battery-based powersupply is that the conventional schemes for delivering power to theimaging components, such as complicated and expensive slipring systemsand bulky cable systems, can be avoided.

As shown in FIGS. 3A and 3B, the battery system 63 is mounted to androtates with the rotor 41. The battery system 63 includes a plurality ofelectrochemical cells. The cells can be incorporated into one or morebattery packs. In one embodiment, for example, the battery system 63includes seven battery packs 64, with sixty-four cells per pack 64, fora total of 448 cells. The battery system 63 is preferably rechargeable,and is recharged by the charging system 34 when the rotor 41 is notrotating. In one embodiment, the battery system 63 consists of lithiumiron phosphate (LiFeP04) cells, though it will be understood that othersuitable types of batteries can be utilized.

The battery system 63 provides power to various components of theimaging system 100. In particular, since the battery system 63 islocated on the rotating portion 101 of the imaging system 100, thebattery system 63 can provide power to any component on the rotatingportion 101, even as these components are rotating with respect to thenon-rotating portion 103 of the imaging system 100. Specifically, thebattery system 63 is configured to provide the high voltages and peakpower required by the generator 45 and x-ray tube 43 to perform an x-rayimaging scan. For example, a battery system may output ˜360V or more,which may be stepped up to 120 kV at a high-voltage generator (which mayalso be located on the rotating portion 101) to perform an imaging scan.In addition, the battery system 63 can provide power to operate othercomponents, such as an on-board computer 46, the detector array 45, andthe drive mechanism 47 for rotating the rotor 41 within the gantry 40.

Each of the battery packs 64 includes an associated control circuit 66,which can be provided on a circuit board. In certain embodiments, thecontrol circuits 66 can communicate with one another and/or with a mainbattery controller that is also located on the rotating portion 101 ofthe imaging system 100.

The battery pack control circuit(s) 66 are configured to monitor and/oralter the state of charge of each of the electrochemical cells 65 in thebattery pack 64. An example of a battery pack control circuit 66 isshown in FIG. 5 . In this embodiment, the control circuit 66 connectsacross each individual cell 65. The control circuit 66 monitors thevoltage of the cell 65, and generates signals from the analog-to-digitalconverter 71 that indicate the charge-state of the cell. These signalsare provided to the main battery controller 67, which monitors thecharge-state of all the cells in the battery system. The controller 67may comprise a processor having an associated memory that may executeinstructions (e.g. software) stored in the memory. The main batterycontroller 67 can send control signals to the respective controlcircuits 66 to alter the state of charge of each electrochemical cell65. In the embodiment of FIG. 5 , the main battery controller 67 altersthe charge-state of the cell 65 by switching on transistor 72, whichconnects the cell 65 across load resistor 73. The cell 65 can then bepartially drained in a controlled manner. The battery controller 67 cancontinue to monitor the charge state of the cell 65 and switch off thetransistor 72 when the cell 65 reaches a pre-determined charge state.

In one embodiment, whenever the cell 65 is in danger of overcharging,the load resistor is switched in until the battery is at a safe chargestate. In certain embodiments, if an overcharge condition is actuallyreached in one or more cells, the charging system can be switched offwhile the load resistor continues to drain the cell. Other cell chargingand balancing schemes can also be employed.

In certain embodiments, the battery system includes processing circuitrythat is configured to implement a control scheme to cause theelectrochemical cells to have substantially the same charge state. Thiscontrol scheme can be implemented by a main battery controller 67, forexample, or can be implemented by the plurality of battery pack controlcircuits 66 in communication with each another. In one exemplaryembodiment of the control scheme for the battery system, a load resistoris switched in for each cell when the cell either exceeds the desiredcharge voltage or when the cell exceeds the average cell voltage by apre-determined threshold. The charging system is disabled if any cellexceeds the maximum charging voltage.

FIG. 6A schematically illustrates the battery system 63, charging system34 and docking system 35 according to one embodiment. The chargingsystem 34 provides electrical power to the battery system 63 in order tocharge the rechargeable electrochemical cells. In a preferredembodiment, the charging system 34 is located on the non-rotatingportion 103 of the imaging system 100. For example, the charging system103 can be located on the gimbal 30, the outer shell 42 of the gantry40, the base 20 or the pedestal 50 (see, e.g., FIGS. 1-3B). In apreferred embodiment, the charging system 34 is located on the gimbal30. FIGS. 3A, 7 and 8 illustrate one embodiment of a charging system 34that is located on the gimbal 30. The charging system 34 is electricallycoupled to the battery system 63 at least during the times when therotating portion 101 of the imaging system 100 is stationary relative tothe non-rotating portion 103, such as in between imaging scans. Thecharging system 100 need not be, and in preferred embodiments is not,electrically coupled to the rotating portion 101 during an imaging scan.In one embodiment, the docking system 35 couples the charging system 34to the battery system 63 when the rotating portion 101 is in astationary or “park” mode, as is described in greater detail below.

The charging system 34 is configured to receive input power from anexternal power source, such as a standard wall power outlet. Thecharging system 34 can include circuitry that conditions the input powerto render it suitable for recharging the battery packs 64 on the rotor41. The charging system 34 can also include control circuitry thatcommunicates with the battery pack control circuit(s) and controls theoperation of the charging system.

In one embodiment, the charging system 34 is configured to automaticallybegin charging of the battery system 63 when the charging system 34 iselectrically coupled to the battery system 63. During the chargingoperation, the battery pack control circuits 66 and/or the main batterycontroller 67 monitor the state of charge of the individual cells 65,and can instruct the charging system 34 to terminate charging when apre-determined charge-state is reached. For example, charging canterminate when one or more of the electrochemical cells 65 reach a fullstate of charge.

The docking system 35 is configured to selectively couple and de-couplethe rotating 101 and non-rotating 103 portions of the imaging system100. As schematically illustrated in FIG. 6A, a first portion 36 a ofthe docking system 35 is located on the rotating portion 101 of thesystem, preferably on the rotor 41, and includes a mating surface thatfaces towards the outer circumference of the gantry 40. A second portion36 b of the docking system 35 is located on the non-rotating portion 103of the system, such as on the gimbal 30, and includes a mating surfacethat faces into the interior housing of the gantry. When the system isin “park” mode, the rotor 41 automatically rotates to a position wherethe first 36 a and second 36 b portions of the docking system 35 arealigned and facing one another. Mating features (e.g., pin(s) andsocket(s)) on one or both of the first 36 a and second 36 b portions ofthe docking system are actuated to physically connect the two portions36 a, 36 b. During an imaging scan, the two portions 36 a, 36 bdisengage from each other, and the first portion 36 a rotates with therotor 41 inside the interior housing of the gantry 40.

The docking system 35 includes at least one electrical connection forproviding power to components on the rotating portion 101, including therechargeable battery system 63. When the docking system 35 isdisengaged, such as during an imaging scan, power for the components ofthe rotating portion 101 comes from the battery system 63. Components onthe non-rotating portion 103 of the imaging system 100 can remainpowered by an external power source, such as grid power.

In one embodiment, the docking system 35 further includes at least oneelectrical connection for data transfer between the rotating andnon-rotating portions of the imaging system 100. The rotating portion101 of the imaging system 100 obtains imaging data at the detector array45, and this data may be transferred off the rotating portion 101 viathe docking system 35 for processing and/or display. In one embodiment,the rotating portion 101 of the imaging system 100 includes a computer46 having a memory and processor. The image data obtained at thedetector 45 may be sent to the computer 46 for temporary storage andoptional processing while the rotating portion 101 is rotating.Following an image scan, the rotating and non-rotating portions of thesystem are connected by the docking system 35, and the data from theon-board computer 46 may be downloaded off the rotating portion 101 forfurther processing and/or display.

An embodiment of a docking system 35 is shown in FIGS. 9A-14B. The firstportion 36 a of the docking system 35 includes a pair of moveable rods51 that reciprocate between a first, disengaged position (FIGS. 9A and9B) and a second, engaged position (FIGS. 10A and 10B). The firstportion 36 a is shown in FIGS. 11A and 11B. An electrical connector 53 ais secured between the rods 51 and moves with the movement of the rods.An actuator, which in this embodiment includes a motor 55 and lead screw56, drives the movement of the rods 51 and connector 53 a. The secondportion 36 b of the docking system 35 is illustrated in FIGS. 12A and12B, which shows a pair of slots 52 and an electrical connector 53 bthat is configured to mate with the connector 53 a on the first portion36 a. During engagement of the docking system 35, the rods 51 from thefirst portion 36 a move into engagement with the corresponding slots 52in the second portion 36 b of the docking system. This engagementprevents the rotating portion 101 from moving relative to thenon-rotating portion 103 while the docking system is engaged.

The rods 51 and slots 52 also ensure that the respective electricalconnectors 53 a, 53 b on the first and second portions 36 a, 36 b areproperly aligned as the actuator mechanism 55, 56 moves the connectors53 a, 53 b into mating engagement. When the docking system 35 is engaged(FIGS. 10A and 10B), the connectors 53 a, 53 b carry electrical power tocharge the battery system, and also enable data and control signals topass between the rotating and non-rotating portions of the system.

FIGS. 13A-14B illustrate the location of the docking system 35 withinthe imaging system 100. As seen most clearly in FIG. 13B, the firstportion 36 b is mounted to and rotates with the rotor 41. Between scans,the rotor 41 rotates to the “park” position of FIG. 13 , and the dockingsystem 35 is engaged. The second portion 36 b of the docking system 35is located on the gimbal 30, as shown in FIGS. 14A-B. In a preferredembodiment, the second portion 36 b is mounted to the bearing on thegimbal that allows the gantry to tilt with respect to the gimbal, suchthat the second portion 36 b rotates with the tilting motion of thegantry, which allows the docking system to dock and undock while thegantry is tilted.

In one embodiment of a docking sequence, the control circuitry on therotor 41 causes the rotor drive mechanism 47 to rotate the rotor to the“park” position, preliminary to docking. Then, the control circuitrycauses the actuator mechanism 55, 56 to drive the rods 51 (fast) to thepoint where the tapered end portions of the rods 51 (see, e.g., FIGS.9A-B) engage with “rollers” that define the slots 52 on the secondportion 36 b of the docking mechanism. Then, the control parameters ofthe rotor drive mechanism are relaxed such that it can be back driven.The mating electrical contacts are then prepared to engage such thatthey are protected from damage during docking, as is discussed furtherbelow. Next, the rods 5 (are driven (slow) to the “docked” positionwhereby the tapered portion of the rods pushes the rotor into alignmentthrough contacting the rollers on the mating dock. The control circuitrythen reads a loopback signal on the dock to determine proper engagement,and once proper engagement is determined, the electrical connections(e.g., power and data connections) between the rotating 101 andnon-rotating 103 portions of the system are engaged. Rotor drive controlparameters are then restored, and the position is assigned within thecontrol software.

FIG. 6B is a schematic illustration of the system power circuitry duringa docking procedure, according to one embodiment. The system is shown ina docked configuration, with the components on the non-rotating portion103, including charger 34 and one or more device(s) 97, which branch offa main power bus 99, electrically connected to the components on therotating portion 101, including battery 63 and one or more device(s) 98,via docking system 35. To un-dock the system, the electrical connectionbetween the rotating 101 and non-rotating 103 components must be broken.However, at the voltages and currents used by the system, as therespective contacts physically separate, the electricity will continueto flow briefly across the gap, forming a spark. This spark tarnishesand erodes the contacts over time, and in some cases can weld thecontacts together.

There is a similar problem when the system re-docks. If the voltages oneach side of the docking system are significantly different, largecurrents may flow through the dock as the two sides of the power systemequalize. These currents can overheat the contacts.

In one embodiment, both of these problems are solved by designing andoperating the system so that the voltage on the non-rotating 103(charger) side is higher than the voltage on the rotating 101 (battery)side whenever the dock is being mated or unmated. That guarantees thatcurrent can only flow in one direction through the dock. Then, beforethe mating or unmating procedure is performed, a switch 93, which can bea solid-state relay (SSR), is opened to prevent current flow in thatdirection (i.e. from the nonrotating to the rotating side). The dockingsystem 35 can then be safely docked or undocked.

An inrush current limiting circuit 94, which can comprise an NTCresistor, for example, is provided in series with the relay 93 toprotect components, including the relay(s) and the docking system 35,against damage from current inrush during a docking procedure when therelay 93 is turned on.

Note that when the system is docked, power is always free to flow fromthe batteries 63 to components on the non-rotating side 103 of thesystem via diode 92 and docking system 35. However, the rotating portion101 cannot receive power from the non-rotating portion unless the relay93 is switched on. The relay 93 can also be used to halt charging of thebatteries in an over-charge or other emergency situation.

In practice, this configuration means that the system generally cannotbe undocked while it is not plugged into the wall (i.e., the entiresystem is being run off the batteries) or when the main/transport drivefor the system is active because this component can draw more power thanthe charger can source. However, neither of these cases is particularlyrestrictive within normal use of the system.

The systems can include additional safety/failsafe features, such asrelays 95, 95 to protect the various device component(s) 97, 98 on boththe non-rotating and rotating sides 103, 101 of the system. For example,in the case where the non-rotating portion 103 loses power during a scan(i.e. with the system un-docked), the system can be configured so thatall the relays 95 on the non-rotating portion 103 automatically turnoff, so that the non-rotating portion 103 is essentially electricallyinert when, after the scan, the rotating portion 101 re-docks. Similarrelays 96 can be provided on the rotating portion 101, for example, toselectively turn off components 98.

In certain embodiments, data transfer between the rotating 101 andnon-rotating 103 portions of the imaging system 100 can be accomplishedusing a slip ring system. With the slip ring system, continuouselectrical contact is maintained between the > stationary and rotatingparts of the imaging system 100. In one embodiment, a conductive ring ispositioned on the outer circumference of the rotating portion 101 andelectrical contacts, such as conductive brush(es), are located on thenon-rotating portion 103 and maintain continuous contact with therotating portion 101 during imaging. During an imaging scan, data istransferred from the rotating to the non-rotating portions via the slipring in real-time. Power to the rotating portion 101 can be providedthrough the docking system 35 to the rechargeable battery system 63, asdescribed above. The slip ring system can therefore be optimized forhigh-speed data transfer. The slip ring system in this embodiment neednot be designed for high-voltage, high-power operation, which can helpminimize the complexity and expense of the slip ring system. In analternative embodiment, a cable system can be used for data transferbetween the rotating and non-rotating portions. As with the slip ringembodiment, the cable system need not be designed for high-voltage,high-power operation, since primary power to the rotating portion isprovided by the rechargeable battery system.

In another alternative embodiment, the rotating portion 101 can includea wireless transmitter for transmitting the data off of the rotatingportion 101 via a wireless communication link. In this embodiment, theimage data need not be transferred over the docking system 35 or aslip-ring or cable system.

The docking system 35 may also be used to transmit control signalsbetween the rotating and non-rotating portions of the imaging system100. The control signals can include, for example, signals from a mainsystem controller 27 (FIG. 6A), located on the non-rotating portion 103to components on the rotating portion 101, such as the x-ray source anddetector, battery system and on-board computer, as well as signals fromthe rotating portion to the non-rotating portion, such as signals fromthe battery system 63 to the charging system 34 with respect to thecharge state of the electrochemical cells. It will be understood thatthese signals can also be sent over a slip ring or cable system or by awireless link, as described above.

As previously discussed, an advantage of the battery-based power supplyof the invention is that the conventional schemes for delivering powerto the imaging components, such as complicated and expensive slip-ringsystems and bulky cable systems, can be avoided. In one embodiment,during an imaging scan the imaging system 100 is essentially severed intwo, with two independent sub-systems (i.e., the rotating andnon-rotating portions) operating independently of one another. This isdifferent from conventional imaging systems, in which the rotatingcomponents remain physically coupled to the non-rotating portion of thesystem, via a cable or slip-ring or the like.

In one embodiment, as shown in FIG. 15 , the present invention includesa non-contact signaling apparatus 74 located at discrete positions onthe rotating and nonrotating portions of the imaging system. Thesignaling apparatus 74 allows for minimal communication between therotating and non-rotating portions of the imaging system. In one aspect,the signaling apparatus 74 functions as a safety mechanism. For example,during an imaging scan, the signaling apparatus 74 on the non-rotatingportion 103 communicates a signal to the rotating portion 101,instructing the rotating portion 101 to continue the scan. This periodicsignaling from the non-rotating portion to the rotating portion enablesthe scan to continue. However, if for any reason the scan needs to beterminated (such as due to a loss of power or because of a patient orclinician safety issue), the signaling apparatus 74 ceases communicationof these “enable scan” signals. This lack of a signal causes therotating component to immediately terminate the scan without having towait for the rotating portion to fully complete the scan and return tothe docking position.

The signaling apparatus 74 can also be used to provide a signal from therotating to the non-rotating portions to continue the scan. For example,if there is a malfunction on the rotating portion of the system (e.g.,the x-ray generator fails to produce radiation, the rotor fails torotate properly, etc.), it does not make sense for the non-rotatingcomponents to continue with the scan. In this embodiment, the scan isautomatically terminated when the rotating portion stops sending signalsto the non-rotating portion via the signaling apparatus 74.

In some embodiments, the signaling apparatus 74 may be used to transmitsynchronization information from the rotating portion 101 to thenon-rotating portion 103 of the imaging system. For example, a signalingapparatus 74 on the rotating portion 101 may communicate a signal to thenon-rotating portion 103 to assist in coordinating various functionsbetween the two portions. In one example, the signaling apparatus 74 maybe used to coordinate a z-axis translation of the gantry 40 relative tothe patient with the rotational motion of the rotor 41. Since the twohalves of the imaging system become physically disconnected during ascan, this allows for the two halves to coordinate when they are goingto start a scan sequence. A typical sequence is for the docking systemto disconnect, the rotor to start accelerating, and then a signal issent from the rotating portion to the non-rotating portion via thesignaling apparatus 74 to trigger the start of the z-axis translation.

The non-contact signaling apparatus 74 may use, for example, optical ormagnetic signals. One embodiment of the signaling apparatus 74 isschematically illustrated in FIG. 15 . In this embodiment, thenon-contact signaling apparatus 74 employs optical signaling, andincludes light-emitting diodes (LEDs) 75 and photo-detectors 76 atdiscrete positions on the rotating 101 and non-rotating 103 portions ofthe imaging system. Two sets of signaling devices, each set consistingof an LED 75 and a photo-detector 76, are located on the non-rotatingportion 103 of the imaging system 100, such as on the gantry 40 or thegimbal 30. Two additional sets of signaling devices, each alsoconsisting of an LED 75 and photo-detector 76, are located on therotating portion 101 of the imaging system 100, and in particular, onthe rotor 41. The two sets of signaling devices on the non-rotatingportion 103 are on opposite sides of the gantry 40; i.e., separated by180 degrees. The two sets on the rotating portion 101 are separated by90 degrees. In this way, the rotating 101 and non-rotating 103 portionsof the imaging system 100 may exchange signals with one another at every90 degrees of rotation of the rotating portion 101.

According to another aspect, the imaging system 100 includes a rotordrive mechanism 47, as shown in FIGS. 3A, 3B and 4F, which drives therotation of the rotating portion 101 relative to the non-rotatingportion 103. One embodiment of the rotor drive mechanism 47 isillustrated in FIGS. 16-19 . In this embodiment, the rotor 41 is drivenby an internal belt drive. The belt 82 extends around the outercircumference of a circular railing 81. The railing 81 (which can beseen in the exploded view of FIG. 3B and in FIG. 4F) is mounted to aninterior wall of the outer shell 42 of the gantry 40. The drivemechanism 47 includes a motor 83, gear 84 and rollers 85, and is mountedto the rotor 41. The belt 82 is looped through the drive mechanism 47,running between each of the rollers 85 and the railing 81, and over thegear 84, as is most clearly illustrated in FIGS. 18 and 19. (When viewedfrom the side, the path of the belt 82 through the drive mechanism 47somewhat resembles the Greek letter omega, £2). The gear 84 is driven bythe motor 83. As the gear 84 rotates, it meshes with the belt 82, whichis held against the railing 81 by the rollers 85. The rotation of thegear 84 causes the drive mechanism 47 to “ride” along the length of thebelt 81, thus driving the rotation of the rotor 41, which is attached tothe drive mechanism 47, around the circumference of the gantry 40.

As shown, for example, in FIGS. 3A and 3B, the drive mechanism 47 ismounted to the rotor 41 beneath the detector array 45, and opposite thex-ray source tube 43. This can be advantageous, since the motorizedcomponents of the drive mechanism 47 can result in EM interference withthe tube that can affect the position of the x-ray focal spot. Byplacing the drive mechanism on the opposite side of the rotor 41 fromthe x-ray source 43, the possibility of EM interference is minimized.

The foregoing method descriptions are provided merely as illustrativeexamples and are not intended to require or imply that the steps of thevarious embodiments must be performed in the order presented. As will beappreciated by one of skill in the art the order of steps in theforegoing embodiments may be performed in any order. Words such as“thereafter,” “then,” “next,” etc. are not necessarily intended to limitthe order of the steps; these words may be used to guide the readerthrough the description of the methods. Further, any reference to claimelements in the singular, for example, using the articles “a” or “the”is not to be construed as limiting the element to the singular.

The various illustrative logical blocks, modules, circuits, andalgorithm steps described in connection with the embodiments disclosedherein may be implemented as electronic hardware, computer software, orcombinations of both. To clearly illustrate this interchangeability ofhardware and software, various illustrative components, blocks, modules,circuits, and steps have been described above generally in terms oftheir functionality. Whether such functionality is implemented ashardware or software depends upon the particular application and designconstraints imposed on the overall system. Skilled artisans mayimplement the described functionality in varying ways for eachparticular application, but such implementation decisions should not beinterpreted as causing a departure from the scope of the presentinvention.

The hardware used to implement the various illustrative logics, logicalblocks, modules, and circuits described in connection with the aspectsdisclosed herein may be implemented or performed with a general purposeprocessor, a digital signal processor (DSP), an application specificintegrated circuit (ASIC), a field programmable gate array (FPGA) orother programmable logic device, discrete gate or transistor logic,discrete hardware components, or any combination thereof designed toperform the functions described herein. A general-purpose processor maybe a microprocessor, but, in the alternative, the processor may be anyconventional processor, controller, microcontroller, or state machine. Aprocessor may also be implemented as a combination of computing devices,e.g., a combination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration. Alternatively, some steps ormethods may be performed by circuitry that is specific to a givenfunction.

In one or more exemplary aspects, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. The steps of a method or algorithm disclosedherein may be embodied in a processor-executable software moduleexecuted which may reside on a computer-readable medium.Computer-readable media includes both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage media may be anyavailable media that may be accessed by a computer. By way of example,and not limitation, such computer-readable media may comprise RAM, ROM,EEPROM, CD-ROM or other optical disk storage, magnetic disk storage orother magnetic storage devices, or any other medium that may be used tocarry or store desired program code in the form of instructions or datastructures and that may be accessed by a computer. Also, any connectionis properly termed a computer-readable medium. For example, if thesoftware is transmitted from a website, server, or other remote sourceusing a coaxial cable, fiber optic cable, twisted pair, digitalsubscriber line (DSL), or wireless technologies such as infrared, radio,and microwave, then the coaxial cable, fiber optic cable, twisted pair,DSL, or wireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,includes compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk, and blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.

Combinations of the above should also be included within the scope ofcomputer-readable media. Additionally, the operations of a method oralgorithm may reside as one or any combination or set of codes and/orinstructions on a machine readable medium and/or computer-readablemedium, which may be incorporated into a computer program product.

The preceding description of the disclosed aspects is provided to enableany person skilled in the art to make or use the present invention.Various modifications to these aspects will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other aspects without departing from the scope of theinvention. Thus, the present invention is not intended to be limited tothe aspects shown herein but is to be accorded the widest scopeconsistent with the principles and novel features disclosed herein

1. A method of imaging an object using an imaging system that comprisesa first portion having a battery system having a plurality of batterypower sources and a second portion having a charging system, the methodcomprising: monitoring a state of charge of each of the battery powersources; controlling the state of charge of each of the battery powersources; and rotating the first portion relative to the second portionto obtain an image of an object.
 2. The method of claim 1, wherein thestate of charge is controlled to provide a substantially similar chargestate for each of the battery power sources.
 3. The method of claim 1,further comprising charging the plurality of battery power sources usingthe charging system.
 4. The method of claim 3, further comprisingterminating the charging when one or more of the battery power sourcesreaches a full state of charge.
 5. The method of claim 3, furthercomprising coupling the first portion and the second portion using adocking system to charge the battery power sources using the chargingsystem.
 6. The method of claim 5, further comprising de-coupling thefirst portion and the second portion using the docking system to rotatethe first portion relative to the second portion.
 7. The method of claim1, wherein the object to be imaged comprises a human or animal patientand the images obtained comprise diagnostic images.
 8. A method ofimaging an object using an imaging system having a rotatable portion anda non-rotatable portion, comprising: rotating the rotatable portion withrespect to the non-rotatable portion to obtain an image of the object;engaging a docking system to electrically connect the rotatable portionand the non-rotatable portion and prevent the rotatable portion fromrotating with respect to the non-rotatable portion; and disengaging thedocking system to electrically disconnect the rotatable portion and thenon-rotatable portion during image acquisition.
 9. The method of claim8, further comprising: charging a power source on the rotatable portionwhile the docking system is engaged; and providing power to componentsof the rotatable portion with the power source while the docking systemis disengaged.
 10. The method of claim 8, further comprising maintaininga higher voltage on the non-rotatable portion relative to the rotatableportion while the docking system is engaged or disengaged.
 11. Themethod of claim 8, further comprising opening a relay prior to engagingor disengaging the docking system to prevent current from flowing acrossthe docking system from the non-rotating portion to the rotatingportion.
 12. The method of claim 8, further comprising sendingelectronic data and/or control signals between the rotatable and thenon-rotatable portions via the docking system when the docking system isengaged.
 13. The method of claim 8, further comprising transmitting asignal between the rotatable and non-rotatable portions using anon-contact signaling system provided at one or more discrete locationson both the rotatable and non-rotatable portions of the system while thedocking system is disengaged.
 14. The method of claim 8, wherein theobject to be imaged comprises a human or animal patient and the imagesobtained comprise diagnostic images.
 15. A method of imaging an objectusing an imaging system comprising a rotating portion having a rotor andat least one imaging component mounted to the rotor and a gantry havingan outer shell defining a bore and substantially fully enclosing therotating portion over one or more sides of the rotating portion, theouter shell further comprising a mounting surface for a bearing thatenables the rotating portion to rotate 360 within the outer shell, themethod comprising; positioning an object to be imaged within the bore;rotating the rotating portion within the outer shell of the gantry; andobtaining images of the object using the at least one imaging component.16. The method of claim 15, wherein the object to be imaged comprises ahuman or animal patient and the images obtained comprise diagnosticimages.